2005 was the warmest year on record

EDITOR’S SUMMARY: A new study by NASA indicates that 2005 was the warmest year in at least a century, surpassing 1998. According to their data, the five warmest years over the last century have occurred since 1997: 2005, then 1998, 2002, 2003 and 2004.

NASA also announced that over the past 30 years, the Earth has warmed by 0.6 degrees C or 1.08 degrees F, and 0.8 degrees C or 1.44 degrees F over the past 100 years.

The NASA study follows two studies from the World Meteorological Organization (WMO) and the National Oceanic and Atmospheric Administration (NOAA) released last year that suggested 1998 was the warmest year. According to the NASA researchers, the primary difference among the conclusions is the inclusion of data from the Arctic in the NASA analysis. 2005 appears to have been unusually warm in the Arctic, resulting in significant loss in sea ice.

A release from NASA appears below.

2005 WAS THE WARMEST YEAR IN A CENTURY

NASA/GSFC release

The year 2005 may have been the warmest year in a century, according to NASA scientists studying temperature data from around the world.

Climatologists at NASA’s Goddard Institute for Space Studies (GISS) in New York City noted that the highest global annual average surface temperature in more than a century was recorded in their analysis for the 2005 calendar year.

Images courtesy of the NASA Goddard Institute for Space Studies

The highest global surface temperature in more than a century of instrumental data was recorded in the 2005 calendar year in the GISS annual analysis. However, the error bar on the data implies that 2005 is practically in a dead heat with 1998, the warmest previous year.

Our analysis, summarized in Figure 1 above, uses documented procedures for data over land (1), satellite measurements of sea surface temperature since 1982 (2), and a ship-based analysis for earlier years

Two new reports from government agencies say that 2005 is second warmest year on record. The first from NOAA focuses primarily on weather in the United States, while the second, from the World Meteorological Organization (WMO) looks at global temperatures and weather events. The WMO says that 2005 is currently the second warmest year on record, after 1998. Averaged separately for both hemispheres, 2005 surface temperatures for the northern hemisphere (0.65° C above 30-year mean) are likely to be the warmest and for the southern hemisphere (0.32° C above 30-year mean), the fourth warmest in the instrumental record from 1861 to the present. The WMO notes that 2005 brought unusual weather to parts of the world, including prolonged droughts in Africa, Europe, Australia, the United States, and the Amazon Basin; heavy precipitation and flooding in parts of Asia, Europe, and North and South America; a record Atlantic hurricane season; declines in Arctic sea ice; and greater ozone depletion in the Antarctic and Arctic.

The high death toll in 2005 from tsunamis, hurricanes, typhoons, mudslides, earthquakes, volcanoes, locusts and pandemics can not necessarily be blamed on “natural” disaster, according to the United Nations health agency which today pointed to a complex mix of human and natural factors that led to tragedy in those events. .

This year witnessed the largest financial losses ever as a result of weather-related natural disasters linked by many to human action, more than $200 billion compared to $145 billion in 2004, the previous record, according to statistics presented to the United Nations Climate Change Conference currently meeting in Montreal, Canada.

Carbon dioxide levels are now 27 percent higher than at any point in the last 650,000 years, according to research into Antarctic ice cores published on Thursday in Science

Some other research groups that study climate change rank 2005 as the second warmest year, based on comparisons through November. The primary difference among the analyses, according to the NASA scientists, is the inclusion of the Arctic in the NASA analysis. Although there are few weather stations in the Arctic, the available data indicate that 2005 was unusually warm in the Arctic.

In order to figure out whether the Earth is cooling or warming, the scientists use temperature data from weather stations on land, satellite measurements of sea surface temperature since 1982, and data from ships for earlier years.

Previously, the warmest year of the century was 1998, when a strong El Niño, a warm water event in the eastern Pacific Ocean, added warmth to global temperatures. However, what’s significant, regardless of whether 2005 is first or second warmest, is that global warmth has returned to about the level of 1998 without the help of an El Niño.

The result indicates that a strong underlying warming trend is continuing. Global warming since the middle 1970s is now about 0.6 degrees Celsius (C) or about 1 degree Fahrenheit (F). Total warming in the past century is about 0.8* C or about 1.4* F.

“The five warmest years over the last century occurred in the last eight years,” said James Hansen, director of NASA GISS. They stack up as follows: the warmest was 2005, then 1998, 2002, 2003 and 2004.

Over the past 30 years, the Earth has warmed by 0.6* C or 1.08* F. Over the past 100 years, it has warmed by 0.8* C or 1.44* F.

Current warmth seems to be occurring nearly everywhere at the same time and is largest at high latitudes in the Northern Hemisphere. Over the last 50 years, the largest annual and seasonal warmings have occurred in Alaska, Siberia and the Antarctic Peninsula. Most ocean areas have warmed. Because these areas are remote and far away from major cities, it is clear to climatologists that the warming is not due to the influence of pollution from urban areas.